1. Field of the Invention
This invention relates to an apparatus for automatically winding wire, preferably fine wire, in what is termed in the art as perfect layer coil winding. The placement of the wire in perfect layer winding is characterized by being a non-helix winding, every turn of which is substantially orthocyclic. For further amplification concerning perfect layering, see, for example, U.S. Pat. No. 3,989,200 issued Nov. 2, 1976 to Bachi Inc.
2. Description of the Prior Art
In the past, prior art apparatuses have attempted to maximize the efficiency with respect to obtaining perfect wiring on bobbins of varying sizes and shapes. Thus, for example, in U.S. Pat. No. 3,565,357, issued Feb. 23, 1971 to Tokyo Shibaura Electric Co., Ltd., the teachings of which are incorporated herein by reference, a fine wire winding device is taught. A guide pulley for feeding the length of the wire to a bobbin is arranged to follow a wire winding point on the bobbin with a space and move in parallel with said point with a predetermined inclination, in such a manner that the wire to be wound forms a predetermined angle with respect to the wire already wound about the bobbin. Control means is also provided for mechanically reversing the direction of movement of the guide pulley when the wire winding point approaches the ends of the bobbin, so that the guide pulley may reciprocate to effect the wire winding operation in the reverse direction. The system taught is a purely mechanical system wherein the sensing device for maintaining constant angularity in the wire to be wound and the wire already wound, comprises a bevel bearing riding on a rotating shaft. As the tensioned wire moves along the rotating bobbin, thereby changing the angularity of the wire, the bevel bearing falls off from its normal perpendicular position relative to the rotating shaft. The angularity between the bevel bearing and the rotating shaft causes the guide block upon which the guide arm rests, to move in the direction of the winding thereby re-establishing the predetermined inclination.
Unfortunately, the sensing device utilized in the '357 patent, results in substantial slippage between the bearing and the shaft and a diminution in sensitivity. In addition, the process results in rapid and substantial wear and tear on the shaft. The correcting forces generated by this system are very low, making the system subject to outside forces. If the pre-load on the bearing is increased, the wear factor becomes even greater. Minor contamination of the shaft surface can result in substantial drop-off in winding sensitivity. Furthermore, there are substantial vibrational forces due to the inherent nature of the process causing drop off in sensitivity. Moreover, the neutral position of the arm and wire have to be predetermined and pre-established by way of a springing of the sensing arm. Finally, the process generates such noise that operators must wear ear plugs or other devices to shield themselves from the noise.
Other patents have described winding apparatuses which utilize electric components in the sensing device. Thus, for example, in U.S. Pat. No. 3,779,480 to Cambou, an electrically operated winding system is disclosed. A wheatstone bridge functions as the basis for maintaining the constant angularity required in coil winding. Difficulties, however, have existed in terms of expense in the operation and maintenance of the apparatus as well as in the large number of movable parts.
In U.S. Pat. No. 2,990,136 to Wilkinson, a coil winding apparatus is taught wherein the wire guide is mechanically liked to a rotary fluid control valve which operates to supply fluid to a differential piston such that a translation motion is produced in the wire guide assembly. In Wilkinson, a pneumatic device is taught. The apparatus works against a biassed piston.
In. U.S. Pat. No. 4,022,391 to Stein, there is disclosed a coil winding device which utilizes an electrical angle sensor in the wire guide assembly to produce an error signal which controls a translational motion in the bobbin. Sensing means in Stein senses the gauge of the wire in establishing position.
In all of the above systems, substantial variation in sensitivity has been noted thereby diminishing their utility.
Moreover, the mechanisms require expensive parts which lead to increased costs with respect to their operation. Many of the systems such as taught in U.S. Pat. No. 3,565,357, supra, have high vibrational behavior which results in a substantial decrease in the ability of the system to lay down the wire in a predetermined manner. Furthermore, several of the systems suffer from rapid wear and tear of the component parts.
The instant invention solves many of the problems faced by prior art processes such as those associated with the U.S. Pat. No. 3,565,357. Thus, utilization of the instant winding apparatus results in elimination to a substantial degree of vibronic factors which would result in a decrease in sensitivity; increased wire winding sensitivity; diminution in the wear and tear on the component parts of the systems; substantial reduction in noise generated by operation of the apparatus; and the development of a substantially automatic system which requires little attention by an operator.
Moreover, the instant apparatus, in terms of the cost of the manufacture and operation of the same, results in substantial cost savings.